chore(ffmpeg): add source

Makefile

@@ -5,7 +5,7 @@ override venv ?= ${shell git rev-parse --show-toplevel}/.venv
 create-venv: override python_version ?= 3.12
 create-venv: ${shell which 'python${python_version}'}
 	@python${python_version} -m 'venv' '${venv}'
-	@${venv}/bin/pip --require-virtualenv install -U -r 'requirements.txt'
+	@${venv}/bin/pip --require-virtualenv install -r 'requirements.txt'
 
 recreate-venv:
 	@rm -r '${venv}'

knowledge base/ffmpeg.md

@@ -1,10 +1,9 @@
 # ffmpeg
 
-## Table of contents <!-- omit in toc -->
-
 1. [TL;DR](#tldr)
 1. [Format conversion](#format-conversion)
-   1. [Webm to GIF](#webm-to-gif)
+   1. [WebM to GIF](#webm-to-gif)
+   1. [WebM to MP4](#webm-to-mp4)
 1. [Sources](#sources)
 
 ## TL;DR
@@ -17,7 +16,7 @@ ffmpeg -y -i 'rec.webm' -i 'palette.png' -filter_complex 'paletteuse' -r 10 'out
 
 ## Format conversion
 
-### Webm to GIF
+### WebM to GIF
 
 ```sh
 ffmpeg -y -i 'rec.webm' -vf 'palettegen' 'palette.png'
@@ -25,12 +24,21 @@ ffmpeg -y -i 'rec.webm' -i 'palette.png' -filter_complex 'paletteuse' -r 10 'out
 ```
 
 Here `rec.webm` is the recorded video.<br/>
-The first command creates a palette out of the webm file. The second command converts the webm file to gif using the created palette.
+The first command creates a palette out of the webm file. The second command converts the webm file to gif using the
+created palette.
+
+### WebM to MP4
+
+```sh
+ffmpeg -i 'input.webm' -c 'copy' 'output.mp4'
+ffmpeg -fflags '+genpts' -r '24' -i 'input.webm' 'output.mp4'
+```
 
 ## Sources
 
 - [Convert a webm file to gif]
 - [How to convert a webm video to a gif on the command line]
+- [WebM to MP4 conversion using ffmpeg]
 
 <!--
   References
@@ -39,3 +47,4 @@ The first command creates a palette out of the webm file. The second command con
 <!-- Others -->
 [convert a webm file to gif]: https://mundanecode.com/posts/convert-webm-to-gif
 [how to convert a webm video to a gif on the command line]: https://askubuntu.com/questions/506670/how-to-do-i-convert-an-webm-video-to-a-animated-gif-on-the-command-line
+[webm to mp4 conversion using ffmpeg]: https://stackoverflow.com/questions/18123376/webm-to-mp4-conversion-using-ffmpeg

package.json

@@ -1,6 +1,6 @@
 {
   "devDependencies": {
-    "@commitlint/cli": "^19.2.2",
+    "@commitlint/cli": "^19.3.0",
     "@commitlint/config-conventional": "^19.2.2"
   }
 }

snippets/convert-between-formats.sh

@@ -1,8 +1,12 @@
-#!sh
+#!/usr/bin/env sh
 
 # svg to png
 rsvg-convert -ah '96' 'icon.svg' -o 'icon-96.png'
 
+# webm to gif
+ffmpeg -y -i 'rec.webm' -vf 'palettegen' 'palette.png'
+ffmpeg -y -i 'rec.webm' -i 'palette.png' -filter_complex 'paletteuse' -r 10 'out.gif'
+
 # webm to mp4
 ffmpeg -i 'input.webm' -c 'copy' 'output.mp4'
 ffmpeg -fflags '+genpts' -r '24' -i 'input.webm' 'output.mp4'